Abstract
Background and study aims Recurrence of common bile duct stones (CBDS) in patients treated with endoscopic sphincterotomy (ES) can lead to deterioration in their quality of life. Although the pathology and related factors are unclear, we speculated that proton pump inhibiter (PPI) administration increases the risk of CBDS recurrence by altering the bacterial mixture in the bile duct. Patients and methods The primary endpoint of this retrospective study was recurrence-free period. Several independent variables considered to have a relationship with CBDS recurrence including PPI use were analyzed using a COX proportional hazard model, with potential risk factors then evaluated by propensity score matching analysis. Results A total of 219 patients were analyzed, with CBDS recurrence found in 44. Analysis of variables using a COX proportional hazard model demonstrated that use of PPIs and ursodeoxycholic acid (UDCA), as well as the presence of periampullary diverticula (PD) each had a hazard ratio (HR) value greater than 1 (HR 2.2, P = 0.007; HR 2.0, P = 0.02; HR 1.9, P = 0.07; respectively). Furthermore, propensity score matching analysis revealed that the mean recurrence-free period in the oral PPI cohort was significantly shorter as compared with the non-PPI cohort (1613 vs. 2587 days, P = 0.014). In contrast, neither UDCA administration nor PD presence was found to be a significant factor in that analysis (1557 vs. 1654 days, P = 0.508; 1169 vs. 2011 days, P = 0.121; respectively). Conclusion Our results showed that oral PPI administration is a risk factor for CBDS recurrence in patients who undergo ES.